I have not heard of them. What are your goals for this new 403 ? Stock will be just that. If you are going to rebuild it, your might consider the 9:1 KB pistons from FCRperformance.com or run late 330 head/early 350 heads (67-72 heads) to boost compression.
I do not know where you are located but contact FCRperformance and J&S Machine. Both do excellent work on 403's. Also see dickmiller racing and the latest 650HP 403 that runs on pump gas.
www.dickmillerracing.com
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